Here’s a psychological challenge for anyone over 30 who thinks “kids these days” can’t delay their personal gratification. Before you judge, wait a minute.

It turns out that a generation of Americans now working their way through middle school, high school and college are quite able to resist the prospect of an immediate reward in order to get a bigger one later. Not only that, they can wait a minute longer than their parents’ generation, and two minutes longer than their grandparents’ generation could.

It may not sound like much, but being able to hold out for an extra minute or two at a young age may serve them well in the long run. Research suggests that superior results on a delayed-gratification task during the toddle years is associated with better performance in school and in jobs, healthier relationships, and have even fewer chronic diseases.

Those findings emerge from a new effort to understand how children’s ability to hold out for the promise of more has changed over time. The study, published in the journal of Developmental Psychology, resurrected an experiment that’s become a developmental psychology classic, the so-called “marshmallow test.”

Pioneered in the 1960s by a young Stanford psychology professor, the marshmallow test left a child between the ages of 3 and 5 alone in a room with two identical plates, each containing different quantities of marshmallows, pretzels, cookies or another delicious treat. Before leaving the room “to do some work,” the adult researcher instructed the child that the single treat on one plate could be eaten at any time. But if the child could wait for him to return before eating it, the researcher added, she could have the second, bigger treat instead.

After the experimenter closed the door on the subject, researchers on the other side of a two-way mirror monitored the child’s bout with temptation and recorded how long he or she could hold out before licking or eating the treat.

Replicated many times and followed up by a wide range of researchers, the marshmallow test has earned recognition as a powerful predictor of future performance—at least among the white children of well-educated parents. Compared with kids who lunged for the early reward, those who held out for a bigger prize did better in school, got higher SAT scores, had higher self-esteem and better emotional coping skills, and were less likely to abuse drugs.

Other studies found that children unable to defer gratification were more likely to be the opposite.

By the time U of Minnesota psychologist Stephanie Carlson and colleagues at the U of Washington ran the exact same experiment with 540 kinds from 2002 to 2012, the changes appeared to be real close to 60% of the children tested held out the full 10 minutes for a bigger reward. And only about 12% claimed their reward in the first half-minute.

These kids—like the two earlier cohorts, overwhelmingly white from families with relatively high incomes and educational attainment—are now 11 to 21.

On average, they waited two minutes longer (during a 10-minute period) than those from the 1960s before seizing their reward. And they waited one minute longer than those tested in the 1980s.

Surprised? You’re not alone.

In a survey conducted before performing the new analysis, the study authors found that adults in the U.S. “generally intuit” that children today are less tolerant of delayed gratification and less self-controlled than children were 50 years ago.

Roughly three-quarters of a representative sample of U.S. adults did not believe that children these days would show such self-restraint for a better reward. And parents—Latino parents especially—were overwhelmingly convinced their own kids would not delay gratification as long as they would have when they were 4 years old.

Carlson wasn’t so sure. On the one hand, she wondered how kids’ self-control would hold up under the influence of daily television and amid a dramatic rise in attention deficit and hyperactivity disorder diagnoses.\

On the other hand, she knew that research has chronicled a steady rise in kids’ IQ scores—the so-called Flynn effect—which correlates with executive function. And she knew that a growing portion of kids’ screen time, including video games and some social media, can help them learn to manipulate language and other abstractions to accumulate social approval and other rewards.

Higher preschool enrollment and changes in parenting styles, including the rise of the empowered child, also might contribute to generational improvement in kids’ ability to delay gratification, Carlson said. After all, only 15.7% of all 3- and 4-year-olds in the United States attended preschool in 1968. By the year 2000, more than half of kids that age attended schools that stressed social skills and self-control as cornerstones of educational readiness.

The findings “do make me hopeful,” she said. Not only have qualities such as perseverance and self-control not disappeared, a simple and unchanged measure of those qualities—the marshmallow test—has withstood many trials, including the test of time.

“Delay of gratification is still a good bellwether of these self-regulation and executive function skills, and we’re learning more every day about how important they are for school readiness an achievement.”